CVE-2015-1786 in Zend Framework
Summary
by MITRE
Cross-site request forgery (CSRF) vulnerability in Zend/Validator/Csrf in Zend Framework 2.3.x before 2.3.6 via null or malformed token identifiers.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/15/2019
The CVE-2015-1786 vulnerability represents a critical cross-site request forgery flaw within the Zend Framework 2.3.x series, specifically affecting versions prior to 2.3.6. This vulnerability resides in the Zend/Validator/Csrf component which is responsible for implementing CSRF protection mechanisms in web applications built on the Zend Framework. The flaw manifests when the framework encounters null or malformed token identifiers during the validation process, creating a potential attack vector that could be exploited by malicious actors to bypass security controls designed to prevent unauthorized actions.
The technical implementation of this vulnerability stems from inadequate input validation within the CSRF token handling mechanism. When the system processes CSRF tokens that are null or malformed, the validation logic fails to properly reject these invalid identifiers, allowing attackers to submit forged requests without proper authentication. This represents a direct violation of the principle of least privilege and demonstrates a failure in the framework's security validation controls. The vulnerability aligns with CWE-352, which specifically addresses cross-site request forgery weaknesses in web applications, and can be categorized under the broader category of authentication bypass flaws that compromise the integrity of session management systems.
The operational impact of this vulnerability extends beyond simple security concerns, as it can enable attackers to perform unauthorized actions within the context of authenticated users. An attacker could potentially manipulate the CSRF token validation process to execute malicious operations such as changing user passwords, modifying account settings, or performing financial transactions without proper authorization. This vulnerability particularly affects web applications that rely on Zend Framework's built-in CSRF protection mechanisms, making it a significant concern for organizations maintaining legacy systems or those that have not yet updated to the patched versions. The exploitation of this flaw could lead to complete account compromise, data breaches, and unauthorized access to sensitive system resources.
Organizations affected by this vulnerability should prioritize immediate remediation through updating to Zend Framework 2.3.6 or later versions where the CSRF token validation has been properly patched. The mitigation strategy should include comprehensive testing of all CSRF protection mechanisms to ensure that null and malformed token identifiers are properly rejected. Security teams should also implement additional monitoring and logging around authentication and authorization events to detect potential exploitation attempts. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date security frameworks and the necessity of thorough input validation in all security-critical components. The ATT&CK framework categorizes this as a privilege escalation technique through authentication bypass, highlighting the severity of the potential impact on system security and user data integrity.